Polarography of benzo(a)pyrene and 6-fluorobenzo(a)pyrene showed that the latter has a slightly higher oxidation potential. Proton magnetic resonance studies of the reactions of formaldehyde with amino acids and diamines continued. By competition with histidine for formaldehyde, the equilibrium constants for formation of imidazolidine, hexahydropyrimidine, and 1,3,6,8-tetraazatricyclo[4.4.1.1-3,8]dodecane were determined. The exchange rates of morpholine, piperazine, and N-methyl piperazine with their hydroxymethyl derivatives were found to be faster than predicted from comparison with other amines. To account for this a mechanism involving methylene bridge formation is proposed.